This application is based upon and claims the benefit of priority from Japanese patent application No. 2006-143115, filed on May 23, 2006, the disclosure of which is incorporated herein in its entirely by reference.
The present invention relates generally to a cellular phone system, a cellular phone terminal, a private information protection method, a private information protection program and a program recorded medium, more specifically to a cellular phone system, a cellular phone terminal, a private information protection method, a private information protection program and a program recorded medium for protecting private information stored in a cellular phone terminal.
Generally, a cellular phone terminal or a portable telephone terminal has an address book function in which the user is able to search the address book of the cellular phone terminal for simply dialing a desired telephone number or sending an electronic mail.
Also, a cellular phone terminal has a mail box function for saving electronic mail information of received electronic mails. Moreover, a cellular phone terminal that is capable of gaining access to internet web pages has a bookmark function to register web page URLs for enabling the user to easily gaining access to his/her favorite web pages as disclosed in the following non-patent documents 1 through 4:    Non-patent document 1: Handley, M., Schulzrinne, H., Schooler, E., Rosenberg, J., “SIP: Session Initiation Protocol”, RFC 2543, March 1999    Non-patent document 2: Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., Berners-Lee, T, “Hypertext Transfer Protocol-HTTP/1.1”, RFC 2616, June 1999    Non-patent document 3: Berners-Lee, T., Connolly, D., “Hypertext Markup Language-2.0”, RFC 1866, November 1995    Non-patent document 4: Crispin, M., “INTERNET MESSAGE ACCESS PROTOCOL-VERSION 4 rev1”, RFC 2060, December 1996
However, registration numbers, telephone numbers, electronic mail addresses, bookmark information, electronic mail information and the likes included in the above-mentioned address, bookmark and mailbox functions are private information. In recent years, general public is increasing conscious to protection of private information and it is a social problem that such private information leaks when such cellular phone terminals are lost or stolen.
In order to avoid such problem, there are developed some cellular phone terminals to restrict accessing to the address book and the mail box or dialing by means of password. However, such technique is not sufficient countermeasure against leakage of private information in that considerable burdens are imposed to the user for setting a password or for manually switching to a security mode, which is sometimes failed by the user. Additionally, a cellular phone terminal does not have enough capacity for a password.
Moreover, since mobile centrex is gaining popularity in recent years, cellular phone terminals that can be used also as extensions by a wireless LAN in a company or the like are increasingly popular in a business field. Telephone numbers, mail address information and electronic mail information included in the address book function in such business use cellular phone terminals are clients' confidential information. As a result, the leakage of such confidential information causes immeasurable impact.